Khorne is fun, but not clever enough. It's so simple, it's not theatrical or clever.
Nurgle is gross, though I enjoy a good plague, that shits gross and he ruins Tzeentch's shit all the time. Which is just fucking rude, he spends all that time making a plan and dickface here ruins it.
Slaneesh, that shits just selfish and would get boring after a while.

Tzeentch, with the most power over the warp, the guy who calls together the gods sometimes, the god of the Thousand Sons, The best.

They look cooler in pictures than they do as little plastic models. Because their so small, the crest on their helmet ends up being really thick so it won't break off, making them look very silly. And the scale is weird, so the crest is nearly half as tall as they would be without it.
This is not what the models look like.

fair enough. I'm not quite sure who I would worship... nurgle would be nice because I wouldn't fear death or pain but then khorne gives me the right to kill everyone while slaanesh doesn't really appeal to me and tzeentch I would need to be a psyker sooo

Alpha Plus Psykers are capable of snapping Battle Titans in half with ease, summoning giant fucking hoards of Daemons, destroying entire worlds, they are so unbelievably powerful. One that worships Tzeentch would be fucking incomprehensibly powerful.

If I remember right, Alpha Plus is only even on the Assignment so the Emperor can be Alpha Plus Plus and so people can quantify how OP their character is in bad fanfiction. Human minds can't handle Alpha level psionics, so Alpha Pluses probably just pop like balloons.

I was playing as the Orkz against the Imperial Guard. The Ultimate Apocalypse mod made it interesting. I think I got at least 2000 Orks killed. And after a while it was just a standoff, they wouldn't fucking stop.